#app {
  height: 100vh;
  width: 100vw;
}

#header {
  padding: 8px;
  box-sizing: border-box;
  height: 60px;
  background: #ccc;
}

#header .title {
  font-size: 26px;
  font-weight: 500;
  align-self: center;
}

#header .box {
  font-size: 18px;
}

#bodyer {
  position: relative;
}

#bodyer #mask {
  position: absolute;
  left: 0;
  top: 0;
  height: 750px;
  width: 750px;
  background: rgba(0, 0, 0, 0.5);
}

#bodyer #mask #start-btn {
  border: none;
  border-radius: 4px;
  background: darkorange;
}

#bodyer #canvas {
  display: block;
  background: #ccc;
}

#footer {
  padding: 8px;
  line-height: 26px;
  font-size: 16px;
  box-sizing: border-box;
  background: #ccc;
}

#footer .title {
  font-weight: bold;
}

#footer .p {
  text-indent: 2em;
}
